Chapter 4 The Water Planet

1
Chapter 4 The Water Planet

• II. WATER RESOURCES

2
II. WATER RESOURCES

• A. Surface water

3
A. Surface water

• Headwaters are formed from the runoff of
  precipitation toward the lowlands and coasts

4
A. Surface water

• Headwaters are the first and smallest streams to
  form from this runoff

5
A. Surface water

• Tributaries are any smaller stream or river that
  flow into a larger stream or river

Tributaries of the vena cava
                                       
6
A. Surface water

• A watershed is an area of land that is drained by
  a river and its tributaries

7
A. Surface water

• Rivers are a valuable resource, providing water
  for agriculture, electricity, transportation, and
  cities

8
A. Surface water

• An estuary is where rivers meet an arm of the sea

9
A. Surface water

• Estuaries are semi-enclosed bodies of fresh water
  and seawater that are rich in fish and shellfish

10
A. Surface water

• Lakes are formed when runoff water fills a
  depression on the land surface

11
A. Surface water

• Most Lakes are fresh water, except for some like
  the Great Salt Lake

The Great Salt Lake is a remnant of the massive
ancient Lake Bonneville. The lake is now
landlocked and its waters are salty The salinity
of the water averages about 12, making it much
saltier than the ocean. The water is so buoyant
that people can easily float
12
A. Surface water

• Lakes are different from seas

13
A. Surface water

• Lakes
• Totally surrounded by land
• Are usually not at sea level
• Do not exchange water with oceans

14
A. Surface water

• Wetlands are land areas that become flooded for
  at least part of the year

15
A. Surface water

• The Everglades in Florida are one of the
  best-known wetlands

16
B. Groundwater

• Groundwater is beneath the surface of the land
  found in spaces between rocks and soil

17
B. Groundwater

• Water seeps downward and stops when the spaces
  in the ground are saturated

18
B. Groundwater

• The top of this saturated layer is called the
  water table

19
B. Groundwater

• Groundwater flows through layers of rock to form
  an aquifer

20
C. The oceans

• Oceans cover about 71 of the earths surface

21
C. The oceans

• Oceans are one continuous global body of water
  surrounding the continents

22
C. The oceans

• This global ocean is divided into four separate
  oceans
• Atlantic
• Pacific
• Indian
• Arctic

23
C. The oceans

• The Pacific Ocean is the largest feature on
  Earth, covering an area larger than all the
  continents combined

24
C. The oceans

• The Atlantic and Indian Oceans are each about
  half the size of the Pacific

25
C. The oceans

• The Arctic Ocean is the smallest ocean

26
C. The oceans

• Smaller bodies of salt water include seas, which
  are connected to the oceans

27
Seas of the world
28
C. The oceans

• Gulfs are near coasts and extend into the land -
  usually larger, more enclosed, and more deeply
  indented than bays

29
C. The oceans

• Bays are inlets of seas

30
C. The oceans

• Ocean depths varies greatly
• The most shallow part of the ocean is the
• continental shelf, which slopes downward
• from the continent

The continental shelf slants from the shore's
low-tide line to the continental slope, a cliff
that plunges abruptly to the deep Ocean floor.
The shelf can be a few miles wide to over 200
miles, reaching a depth of 450 feet. It collects
most of the sand, silts and other sediments from
rivers. The eastern continental shelf of the US
is over 3 times as wide as that on the West Coast
31
C. The oceans

• The greatest ocean depth is in the Mariana
  Trench, located in the North Pacific Ocean

32
D. Characteristics of seawater

• Seawater contains every element known on the
  earth, even gold

33
D. Characteristics of seawater

• Salts are the most common material found in
  seawater and about 3.5 of seawater is dissolved
  salts

34
D. Characteristics of seawater

• Because of its salt content, people cannot use
  seawater for drinking or for agriculture

Drinking seawater promotes dehydration because
seawater is a thirsty solution. As the seawater
flows through the stomach and intestine it draws
water out of bodily tissues. Seawater has a lower
concentration of water than pure water has
(because of the salt!), so water molecules will
migrate toward seawater. If the seawater is in a
person's stomach or intestines, water will move
toward the seawater from the body's tissues,
resulting in dehydration.
35
D. Characteristics of seawater

• Desalination is an expensive method to remove
  salt from seawater

36
D. Characteristics of seawater

• Oceans do not have the temperature extremes of
  land

37
D. Characteristics of seawater

• The ocean waters are always moving and
  circulating